Fix hf when import with verify off

Delete the hf tables, so the next open will rescan and regenerate

src/blockchain_db/berkeleydb/db_bdb.h

@@ -375,6 +375,7 @@ private:
   virtual uint64_t get_hard_fork_starting_height(uint8_t version) const;
   virtual void set_hard_fork_version(uint64_t height, uint8_t version);
   virtual uint8_t get_hard_fork_version(uint64_t height) const;
+  virtual void check_hard_fork_info();
 
   /**
    * @brief convert a tx output to a blob for storage